function meanR2_model = model_meanR2(beta,t)
nu = beta(1);
sigma2 = beta(2);

meanR2_model = zeros(length(t),1);
mode = 100;
for i = 1:length(t)
    meanAlpha2 = zeros(1,mode);
    meanBeta2  = zeros(1,mode);
    for j = 1:mode
        temp  = sigma2/(2*nu*j^2);
        temp2 = exp(-2*nu*t(i)*j^2);
        meanAlpha2(j) = temp+(meanAlpha2(j)-temp)*temp2;
        meanBeta2(j)  = temp+(meanBeta2(j)-temp)*temp2;
    end
    meanR2_model(i) = sum(meanAlpha2+meanBeta2)/(2*pi);
end
end